1. Field of the Invention
This invention relates to an emergency visual assistance device which provides an operator at an operator station access to operationally necessary visual information when that visual information is obscured by smoke or other vision-obstructing matter.
2. Description of the Related Art
In spite of the long history of smoke and fire emergencies aboard aircraft in flight, tragedies with substantial loss of life are still occurring on a regular basis simply because an aircraft cockpit becomes filled with vision-obstructing smoke. In too many of these situations, the inability of the flight crew to see through the smoke causes the flight crew to lose control of the aircraft. This is because they can no longer see the aircraft's instruments, or see outside the aircraft's cockpit. In addition, even when a flight crew can maintain control of the aircraft under these conditions, limited visibility often prevents the flight crew from taking the corrective actions necessary to halt the ingress of smoke into the cockpit. Thick smoke prevents the flight crew from reading emergency checklists, or from operating the switches, circuit breakers, and other controls called out by these checklists.
There are only four patents, all by Werjefelt [U.S. Pat. No. 4,832,287 (1989), U.S. Pat. No. 5,202,796 (1993), U.S. Pat. No. 5,318,250 (1994), and U.S. Pat No. 5,947,415 (1999)], that attempt to address the need for continued access to visual information in an enclosed smoke-filled environment. Werjefelt's patents all relate to inflatable systems that have an undeployed and deployed state. These systems suffer from several disadvantages:
(a) These devices are actually complex mechanical systems, with various mechanical, electrical, and pneumatic components that are subject to mechanical failure and inspection intervals. PA1 (b) The major component of the prior art is a flexible plastic material that can be vulnerable to puncture or tearing. Such a defect during use would make the device useless. PA1 (c) These devices have a deployed and undeployed state. In an emergency situation where contaminants are invading the visual field, these inflatable devices must be manipulated from a storage container and deployed using a compressed gas cylinder or pump before they are functional for the purpose they are designed for. This requires precious time and effort from the flight crew. PA1 (d) These devices are large and bulky in the deployed state, and are not designed to be maneuverable over and around obstructions, such as flight control yokes, power levers, etc. This makes identification and manipulation of many switches and circuit breakers, which are often located above or behind a pilot's head, difficult if not impossible. PA1 (e) These devices have proven quite expensive to manufacture. Because each device is custom-manufactured for the aircraft type and pilot seat position it is to be used in, the cost to produce and purchase these devices is high. PA1 (f) These devices are relatively heavy in comparison to other items of emergency equipment typically carried in an aircraft cockpit. Weight is a critical factor in any decision involving the selection of aircraft equipment, and there is no requirement that aircraft operators carry any device which allows the pilot to see in heavy smoke. PA1 (a) To provide an emergency visual assistance device which is mechanically simple, reliable, and has no moving parts upon which the functionality of the device depends; PA1 (b) To provide an emergency visual assistance device that is constructed from rigid, rugged materials which are unlikely to be damaged--either before the device is used, or during actual use of the device; PA1 (c) To provide an emergency visual assistance device that is always ready for use, and requires no inflation, deployment, or other preliminary steps before it can be effective; PA1 (d) To provide an emergency visual assistance device that is readily positionable and repositionable to provide an operator with an unobstructed view of whatever sources of visual information he/she deems necessary; PA1 (e) To provide an emergency visual assistance device that is inexpensive to manufacture; and PA1 (f) To provide an emergency visual assistance device that is lightweight. Further objects and advantages will become apparent from a consideration of the ensuing drawings and description.
The devices described in the prior art have been designed primarily to allow for the viewing of the instrumentation immediately in front of the pilot and the environment outside an aircraft's windows. They have not focused on the need to complete tasks inside the aircraft.
One element of Werjefelt's invention illustrated in U.S. Pat. No. 4,832,287 (1989) is a hand-held device that would appear to serve a similar function as this invention. However, the description of the device states that it is an inflatable component, not readily usable without first being deployed, and that it is to be used in conjunction with other elements of the invention. Werjefelt also describes it as having a handle that when inflated, would make the component vulnerable to ripping or tearing.